Option to be able to revert to older firmware

Hey,

now with the new firmware the option to immediately install an update and also to delay it were introduced.

But every update not only brings new features and bugfixes. Often times there also new bugs introduced which effect one or another. In this case it would be nice to have the option to revert to a certain firmware.

Please have a look at this topic and I really hope to see an implementation some day.